JPH0970451A - Cover material composition for golf ball - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a cover material for golf balls having a good repulsive property, the soft ball hitting feel equiv. to that of a rubber-thread winding golf ball, excellent durability and good appearance by using a compsn. contg. a thermoplastic polyamide elastomer and a polyamide resin at respectively specific ratios. SOLUTION: The cover material compsn. of the two-piece golf ball formed by covering a core consisting of a rubber compsn. with the cover material is prepd. from 90 to 60 pts.wt. thermoplastic polyamide elastomer and 10 to 40 pts.wt. polyamide resin. A thermoplastic polyamide elastomer having Shore D hardness of <=50 is used for the thermoplastic polyamide elastomer. Polyamide resins having Rockwell hardness of >=100 in R scale, i.e., at least one kind selected from a group consisting of nylon 11, nylon 12, nylon 610, nylon 612, nylon 6, nylon 66, nylon MX6 and nylon 46 are used for the polyamide resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cover material composition for golf balls, which has good resilience, a soft shot feeling equivalent to that of a wound golf ball, excellent durability, and a good appearance. Regarding things.

[0002]

2. Description of the Related Art Generally used golf balls include thread wound golf balls and two-piece golf balls. A two-piece golf ball is formed by covering a core made of a rubber composition with a cover material such as an ionic ethylene-based copolymer resin having excellent impact resistance and resilience. Two-piece golf balls are used by many golfers because of their long flight distance and excellent durability. However, many golfers prefer the soft feel of a thread-wound golf ball to hit feeling because of a hard feeling at the time of hitting, and in recent years, a two-piece golf ball having a soft feel close to that of a thread-wound golf ball. The development of is desired.

Conventionally, it has been proposed to use a thermoplastic polyamide elastomer as a golf ball cover material in order to soften a two-piece golf ball to give a soft feel at impact (JP-A-54-126137). However, in this case, the resilience was insufficient. A method of blending a thermoplastic polyamide elastomer and an ionomer resin has also been proposed (Japanese Patent Laid-Open No. 4-244174), but since both resins are incompatible with each other, a problem of causing appearance defects such as surface fluffing after the polishing step is a problem. was there.

[0004]

SUMMARY OF THE INVENTION The present invention provides a golf ball cover which has good resilience, a soft shot feeling equivalent to that of a thread-wound golf ball, excellent durability, and a good appearance. An object is to provide a wood composition.

[0005]

The golf ball cover material composition of the present invention comprises a thermoplastic polyamide elastomer 90.
It is characterized by comprising -60 parts by weight and a polyamide resin of 10-40 parts by weight. As described above, since the thermoplastic polyamide elastomer and the polyamide resin are used, the resilience is good, the ball has a soft shot feeling equivalent to that of the thread-wound golf ball, and the durability is excellent and the appearance is good. It becomes possible to obtain a cover material composition for golf balls.

[0006]

DETAILED DESCRIPTION OF THE INVENTION The constitution of the present invention will be described in detail below. (1) Thermoplastic polyamide elastomer Since the thermoplastic polyamide elastomer has a polyamide component in its molecule, the compatibility with the polyamide resin is better than that of other thermoplastic elastomers. Further, the lower the hardness of the thermoplastic polyamide elastomer is, the higher the impact resilience is, and therefore, it is more effective as a component for softening the cover material.

As the thermoplastic polyamide elastomer, nylon 6 and nylon 1 are used as hard segments.
1, a block copolymer having nylon 12, a polyamide component such as aromatic polyamide, and a polyoxyalkylene glycol such as polyoxytetramethylene glycol or polyoxypropylene glycol as a soft segment or an aliphatic polyester Can be used.

This thermoplastic polyamide elastomer is
Shore D hardness 50 or less, preferably Shore D hardness 30 to
50's. The Shore D hardness of 30 to 50 is preferable because the thermoplastic polyamide elastomer having a Shore D hardness of less than 30 has a low content of the polyamide component in the hard segment and thus has poor compatibility with the polyamide resin. On the other hand, when the Shore D hardness exceeds 50, the effect of softening the cover material is small and the shot feeling is not improved.

This thermoplastic polyamide elastomer is commercially available as PEBA manufactured by Atochem.
X2533, PEBAX3533, PEBAX4033, Daicel-Huls's Daiamide-PAE E40, Daiamide-PAE E47, Ems Japan's Grillon, Grillamide, Dainippon Ink's Grelax A, Mitsubishi Kasei's Novamid E
L, UBE-PAE, etc. made by Ube Industries. (2) Polyamide resin This polyamide resin is an aliphatic polyamide resin, for example, nylon 11, nylon 12, nylon 610, nylon 612, nylon 6, nylon 66, nylon M.
It is at least one selected from the group consisting of XD6 and nylon 46. It may be an aromatic polyamide resin.

The polyamide resin has a Rockwell hardness of 100 or more on the R scale. (3) Golf ball cover material composition of the present invention 90 to 60 parts by weight of the above-mentioned thermoplastic polyamide elastomer and 10 to 40 parts by weight of polyamide resin. Total of these 10
0 parts by weight.

The reason why the thermoplastic polyamide elastomer is 90 to 60 parts by weight is that the cover material is too soft and the resilience is poor if it exceeds 90 parts by weight, and if it is less than 60 parts by weight, the mixing effect of the thermoplastic polyamide elastomer appears. In addition, since the cover material is hard, the shot feeling is different from that of the thread-wound golf ball. For mixing, rolls, Banbury mixers, extruders for plastics, especially twin-screw extruders are preferable, and the cylinder and die head temperatures are 150-
It is recommended to carry out at 300 ° C. If necessary, additives such as antioxidants, stabilizers, lubricants, colorants and the like may be appropriately added. In addition, an elastomer other than the thermoplastic polyamide elastomer, an ethylene-α-olefin copolymer, or the like may be added as appropriate. Elastomers other than thermoplastic polyamide elastomers include polyester elastomers, polyurethane elastomers, polyolefin elastomers, polystyrene elastomers, and vinyl chloride elastomers. As the ethylene-α olefin copolymer,
There are AFFINITY POP and ENGAGE POE manufactured by Dow Chemical Co., which are copolymers of ethylene and octene.

[0012]

[Examples] According to the formulation (parts by weight) shown in the upper part of Table 1, melt kneading was performed at a temperature of 220 ° C using a twin-screw extruder. The resulting composition was 38.3 mm in diameter and 2.54
With a solid core with a compression value of 40 kgf during mm deformation
A golf ball was obtained by coating with a thickness of 2.2 mm by injection molding. The characteristics of each ball are shown in Table 1.

[0013]

[Table 1]

Note) * 1 Thermoplastic PEBAX3533 manufactured by ATOCHEM, Shore D hardness 35. * 2 ATOCHEM thermoplastic PEBAX4033, Shore D hardness 40. * 3 Toray Lilsan BMN 0, Rockwell hardness R
105. * 4 Toray Lilsan AMN 0, Rockwell hardness R
108. * 5 Mimi DuPont Polychemical Co., Ltd., Himilan 160
5, Shore D hardness 67. * 6 Himilan 170 manufactured by Mitsui DuPont Polychemical
6, Shore D hardness 66. * 7 PEBAX6333 made by ATOCHEM, Shore D hardness 63. * 8 Measured at 23 ° C using a Shore D hardness tester (ASTM D224
0). * 9 Relative value when Comparative Example 1 is set to 100, which is the initial velocity ratio of the golf ball to the head speed when hit with a driver (Wood club # 1) at a head speed of 43 m / sec using a swing robot. * 10 The relative number of times when Comparative Example 1 was set to 100, which is the number of hits until a crack occurs when hit with a driver (Wood Club # 1) at a head speed of 43 m / sec using a swing robot. * 11 Driver by a professional golfer (Wood club
The feeling of hitting with # 1). * 12 Visual inspection of the ball surface after painting. As is clear from Table 1, Examples 1 to 4 have a better appearance than Comparative Examples 1 to 5, and have good resilience and durability and a soft shot feeling.

[0015]

As described above, according to the present invention, since the thermoplastic polyamide elastomer and the polyamide resin are blended, the resilience is good, and the golf ball has a soft shot feeling equivalent to that of a thread-wound golf ball, and It is possible to provide a golf ball cover material composition having excellent durability and a good appearance.

Claims (4)

[Claims] 1. A thermoplastic polyamide elastomer 90-60.
A golf ball cover material composition comprising 10 parts by weight of a polyamide resin and 10 to 40 parts by weight of a polyamide resin. 2. The golf ball cover material composition according to claim 1, wherein the thermoplastic polyamide elastomer has a Shore D hardness of 50 or less. 3. The golf ball cover material composition according to claim 1, wherein the polyamide resin has a Rockwell hardness R scale of 100 or more. 4. The polyamide resin is at least one selected from the group consisting of nylon 11, nylon 12, nylon 610, nylon 612, nylon 6, nylon 66, nylon MXD6 and nylon 46. 3. The golf ball cover material composition according to item 3.